docs: def clone(cls, objective, model=None, **kwargs):
          """
          Make a copy of an objective. The objective being copied can be of the same type or belong to
          a different solver interface.
  
          Example
          ----------
          >>> new_objective = Objective.clone(old_objective)
          """
          return cls(cls._substitute_variables(objective, model=model), name=objective.name,
                     direction=objective.direction, sloppy=True, **kwargs)